The present invention relates to the field of system controllers. More particularly, the present invention relates to system controllers for systems having an inherent delay between a command input and a system output.
It is commonly found in control systems that a phenomenon known as integrator overshoot may occur if compensators having integrators are used with systems having an inherent time delay. A typical control system will have a command input that is summed with a feedback signal to create an error signal. The error signal is applied to an input of a compensator, which usually has an integrator component to drive the error signal to zero. The output of the compensator is applied to the input of the control system. For a system with 100 percent feed-forward, an overshoot may occur following a change in the input command. In particular, due to the inherent delay of the system, an error signal provided to the compensator is generally transiently larger than that needed in order to have the system output track the command signal.
Since overshoot is typically undesirable, there is an ongoing need for a controller that can minimize or reduce the extent and/or duration of overshoot in a control system having an inherent delay.